(19)
(11) EP 1 302 647 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
09.08.2006 Bulletin 2006/32

(43) Date of publication A2:
16.04.2003 Bulletin 2003/16

(21) Application number: 02022878.9

(22) Date of filing: 14.10.2002
(51) International Patent Classification (IPC): 
F02D 41/02(2006.01)
 F01N 3/08(2006.01)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LI LU MC NL PT SE SK TR
Designated Extension States:
AL LT LV MK RO SI

(30) Priority: 15.10.2001 JP 2001317192
27.12.2001 JP 2001397875

(71) Applicant: Toyota Jidosha Kabushiki Kaisha
Toyota-shi, Aichi-ken, 471-8571 (JP)

(72) Inventors:
  • Kako, Junichi
    Toyota-shi, Aichi-ken, 471-8571 (JP)
  • Nagai, Toshinari
    Toyota-shi, Aichi-ken, 471-8571 (JP)
  • Katoh, Naoto
    Toyota-shi, Aichi-ken, 471-8571 (JP)
  • Katayama, Akihiro
    Toyota-shi, Aichi-ken, 471-8571 (JP)
  • Matsumoto, Kentaro
    Toyota-shi, Aichi-ken, 471-8571 (JP)
  • Kojima, Shinji, Kabushiki K. Toyota Chuo Kenkyusho
    Aichi-gun, Aichi-ken 480-1192 (JP)
  • Baba, Naoki, Kabushiki K. Toyota Chuo Kenkyusho
    Aichi-gun, Aichi-ken 480-1192 (JP)

(74) Representative: TBK-Patent 
Bavariaring 4-6
80336 München
80336 München (DE)

   


(54) Exhaust gas purification system for internal combustion engine


(57) An exhaust gas purification system comprises a NOx catalyst for absorbing the NOx in the exhaust gas when the air-fuel ratio of the influent exhaust gas is lean and purifying by reducing the absorbed NOx with a reducing agent in the exhaust gas when the air-fuel ratio of the exhaust gas turns rich, a first unit for calculating the amount of NOx absorbed per unit time in each area of the NOx catalyst when the air-fuel ratio of the exhaust gas flowing into the NOx catalyst is lean, and a second unit for calculating the total amount of NOx absorbed into the NOx catalyst by totaling the amounts of NOx calculated by the first calculation unit for the areas of the NOx catalyst.







Search report